The goal of the research outlined in this proposal is the development of new, efficient, and stereoselective methods for the synthesis of isoprenoid- type trisubstituted olefins, such as those found in insect juvenile hormones and pheromones. A variety of approaches will be investigated: (1) synthesis from rigid, cyclic precursor (heterocycles; alpha-ketols), (2) rearrangements ((3,3)- and (2,3)- sigmatropic type), (3) coupling of units with preformed stereochemistry (alkylation of unsaturated ester enolates; vinylic-homoallylic coupling), and (4) stereoselective reagents (conjugate reduction of unsaturated epoxides and ketones). In each case the scope and limitations of the reaction will be investigated in model systems, and if promising, the reaction will then be applied to the synthesis of naturally occurring materials.